Percutaneous valve prosthesis and system and method for implanting the same

ABSTRACT

A method for delivering a heart valve prosthesis to a native valve annulus comprises expanding an expandable frame at the native valve annulus and positioning a replacement heart valve within the expandable frame. The expandable frame preferably includes a first anchoring portion that is positioned on a first side of the native valve annulus and a second anchoring portion that is positioned on a second side of the native valve annulus. The first anchoring portion engages tissue on the first side of the native valve annulus and the second anchoring portion engages tissue on the second side of the native valve annulus for securing the expandable frame to the native valve annulus. The replacement heart valve comprises a plurality of leaflets for replacing the function of the native valve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/309,680, which is a national stage entry of International ApplicationNo. PCT/US2007/016855, filed Jul. 27, 2007, which designates the UnitedStates and was published in English by the International Bureau on Jan.31, 2008 as WO 2008/013915, which claims the benefit of U.S. ProvisionalApplication No. 60/833,791, filed Jul. 28, 2006, which is incorporatedherein by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to heart valve prostheses, preferably toaortic valve prostheses. More specifically, the invention relates toheart valve prostheses that can be implanted percutaneously by means ofa catheter from a remote location without opening the chest cavity.

2. Related Art

Heart valve surgery is used to repair or replace diseased heart valves.Valve surgery is an open-heart procedure conducted under generalanesthesia. An incision is made through the patient's sternum(sternotomy), and the patient's heart is stopped while blood flow isrerouted through a heart-lung bypass machine.

Valve replacement may be indicated when there is a narrowing of thenative heart valve, commonly referred to as stenosis, or when the nativevalve leaks or regurgitates. When replacing the valve, the native valveis excised and replaced with either a biologic or a mechanical valve.Mechanical valves require lifelong anticoagulant medication to preventclot formation around the valve, which can lead to thromboemboliccomplications and catastrophic valve failure. Biologic tissue valvestypically do not require such medication. Tissue valves can be obtainedfrom cadavers (homografts) or can be from pigs (porcine valve) and cows(bovine pericardial valves). Recently equine pericardium has also beenused for making valves. These valves are designed to be attached to thepatient using a standard surgical technique.

Valve replacement surgery is a highly invasive operation withsignificant concomitant risk. Risks include bleeding, infection, stroke,heart attack, arrhythmia, renal failure, and adverse reactions to theanesthesia medications, as well as sudden death. Two to five percent ofpatients die during surgery.

Post-surgery, patients temporarily may be confused due to emboli andother factors associated with the heart-lung machine. The first two tothree days following surgery are spent in an intensive care unit whereheart functions can be closely monitored. The average hospital stay isbetween one and two weeks, with several more weeks to months requiredfor complete recovery.

In recent years, advancements in minimally invasive, endoaortic, surgeryinterventional cardiology, and intervention radiology have encouragedsome investigators to pursue percutaneous replacement of the aorticheart valve. Percutaneous Valve Technologies (“PVT”) of Fort Lee, N.J.,has developed a balloon-expandable stent integrated with a bioprostheticvalve, which is the subject of U.S. Pat. Nos. 5,411,552, 5,840,081,6,168,614, and 6,582,462 to Anderson et al. The stent/valve device isdeployed across the native diseased valve to permanently hold the valveopen, thereby alleviating a need to excise the native valve and toposition the bioprosthetic valve in place of the native valve. PVT'sdevice is designed for delivery in a cardiac catheterization laboratoryunder local anesthesia using fluoroscopic guidance, thereby avoidinggeneral anesthesia and open-heart surgery. The device was firstimplanted in a patient in April of 2002.

PVT's device suffers from several drawbacks. Deployment of PVT's stenthas several drawbacks, including that there is very little control overits deployment. This lack of control can endanger the coronary osteaabove the aortic valve and the anterior leaflet of the mitral valvebelow the aortic valve.

Another drawback of the PVT device is its relatively largecross-sectional delivery profile. This is largely due to fabricating thetri-leaflet pericardial valve inside a robust stainless steel stent.Considering they have to be durable, the materials for the valve and thestent are very bulky, thus increasing the profile of the device. The PVTsystem's stent/valve combination is mounted onto a delivery balloon,making retrograde delivery through the aorta challenging. An antegradetransseptal approach may therefore be needed, requiring puncture of theseptum and routing through the mitral valve, which significantlyincreases complexity and risk of the procedure. Very few cardiologistsare currently trained in performing a transseptal puncture, which is achallenging procedure by itself.

Another drawback of the PVT device is its lack of fixation provision. Itin effect uses its radial force to hold the stent in the desiredposition. For this to work, sufficient dilatation of the valve area hasto be achieved; but this amount of dilation can cause damage to theannulus. Also, due to its inability to have an active fixationmechanism, the PVT device cannot be used to treat aortic regurgitation.

Another drawback to this system is that it does not address the leakageof blood around the implant, after its implantation.

Other prior art replacement heart valves use self-expanding stents thatincorporate a valve. One such device is that disclosed in U.S. Pat. No.7,018,406 to Seguin et al. and assigned to and made by CoreValve SA. Inthe endovascular aortic valve replacement procedure, accurate placementof aortic valves relative to coronary ostia and the mitral valve iscritical. Standard self-expanding systems have very poor accuracy indeployment, however. Often the proximal end of the stent is not releasedfrom the delivery system until accurate placement is verified byfluoroscopy and the stent typically jumps once released. It is thereforeoften impossible to know where the ends of the stent will be withrespect to the native valve, the coronary ostia, and the mitral valve.The anchoring mechanism is not actively provided (that is, there is nomethod of fixation other than the use of radial force and barbs thatproject into the surrounding tissue and not used as positioning marker(that is, markers seen under fluoroscopy to determine the position ofthe device).

A simple barb as used in the CoreValve device relies mainly on frictionfor holding the position.

Another drawback of prior art self-expanding replacement heart valvesystems is their lack of radial strength. In order for self-expandingsystems to be easily delivered through a delivery sheath, the metalneeds to flex and bend inside the delivery catheter without beingplastically deformed. In arterial stents, this is not a challenge, andthere are many commercial arterial stent systems that apply adequateradial force against the vessel wall and yet can collapse to a smallenough of a diameter to fit inside a delivery catheter withoutplastically deforming. However, when the stent has a valve fastenedinside it, as is the case in aortic valve replacement, the anchoring ofthe stent to vessel walls is significantly challenged during diastole.The force required to hold back arterial pressure and prevent blood fromgoing back inside the ventricle during diastole will be directlytransferred to the stent/vessel wall interface. Therefore the amount ofradial force required to keep the self expanding stent/valve in contactwith the vessel wall and prevent it from sliding will be much higherthan in stents that do not have valves inside of them. Moreover, aself-expanding stent without sufficient radial force will end updilating and contracting with each heartbeat, thereby distorting thevalve, affecting its function and resulting in dynamic repositioning ofthe stent during delivery. Stent foreshortening or migration duringexpansion may lead to improper alignment.

Additionally, the stent disclosed in U.S. Pat. No. 6,425,916 to Garrisonsimply crushes the native valve leaflets against the heart wall and doesnot engage the leaflets in a manner that would provide positiveregistration of the device relative to the native position of the valve.This increases an immediate risk of blocking the coronary ostia, as wellas a longer-term risk of migration of the device post-implantation.Further still, the stent comprises openings or gaps in which thereplacement valve is seated post-delivery. Tissue may protrude throughthese gaps, thereby increasing a risk of improper seating of the valvewithin the stent.

In view of drawbacks associated with previously known techniques forendovascularly replacing a heart valve, it would be desirable to providemethods and apparatus that overcome those drawbacks.

Sadra et al. (U.S. published application No. 20050137701) describes amechanism for anchoring a heart valve, the anchoring mechanism having anactuation system operated remotely. This mechanism addresses thefixation issue; however, considering the irregular shape of the aorticannulus there is a real potential for deforming the prosthetic valveannulus; this may require additional balloon angioplasty to give it itsfinal shape, and also make the new valve more prone to fatigue andfracture. Moreover if full expansion of the stent is prone todeformation, the leaflet coaptation of the valve will be jeopardized.

Sadra et al. (U.S. published application No. 20050137691) describes asystem with two pieces, a valve piece and an anchor piece. The valvepiece connects to the anchor piece in such a fashion that it will reducethe effective valve area considerably. Valve area, i.e., the innerdiameter of the channel after the valve leaflets open, is of primeimportance when considering an aortic valve replacement in a stenoticvalve. Garrison's valve is also implanted in the inner portion of thestent, compromising the effective valve outflow area. Sadra et al.'s andGarrison's valves overlook this very critically important requirement.

The technologies described above and other technologies (for example,those disclosed in U.S. Pat. No. 4,908,028 to Colon et al.; U.S.Published Application No. 2003/0014104, U.S. Published Application No.2003/0109924, U.S. Published Application No. 2005/0251251, U.S.Published Application No. 2005/0203616, and U.S. Pat. No. 6,908,481 toCribier; U.S. Pat. No. 5,607,469 to Frey; U.S. Pat. No. 6,723,123 toKazatchkov et al.; Germany Patent No. DE 3,128,704 A1 to Kuepper; U.S.Pat. No. 3,312,237 to Mon et al.; U.S. Published Application No.2005/0182483 to Osbourne et al.; U.S. Pat. No. 1,306,391 to Romanoff;U.S. Published Application No. 2005/0203618 to Sharkcawy et al.; U.S.Published Application No. 2006/0052802 to Sterman et al.; U.S. Pat. No.5,713,952; and U.S. Pat. No. 5,876,437 to Vanney et al.) also usevarious biological, or other synthetic materials for fabrication of theprosthetic valve. The duration of function and physical deterioration ofthese new valves have not been addressed. Their changeability has notbeen addressed, in the percutaneous situation.

It is to the solution of these and other problems that the presentinvention is directed.

SUMMARY OF THE INVENTION

It is accordingly a primary object of the present invention to provideto methods and apparatus for endovascularly replacing a heart valve.

In is another object of the present invention to provide methods andapparatus for endovascularly replacing a heart valve with a replacementvalve prosthesis using a balloon expandable and/or self expanding valvecage stent upon which a bi-leaflet or tri-leaflet elastic valve isinserted.

It is also a feature of this invention that the valve piece of theimplant is removable, and thus exchangeable, in the event of long ormedium term failure of the implanted valve.

It is another object of this invention to provide maximal valve area tothe out flow tract of the left ventricle, thus minimizing the gradientacross the valve, by using a supra annular implant of the valve piece tothe valve cage stent.

These and other objects are achieved by a heart valve prosthesiscomprising a cylindrical valve cage stent constructed to be implantedpercutaneously in the planar axis of a native valve annulus, the valvecage stent having a superior rim; and an elastic and compressible,multi-leaflet valve insertable percutaneously into the body, the valveincluding a valve frame made from a memory metal and a tissue coverattached to the valve frame; and attachment means for attaching thevalve to the superior rim of the valve cage.

The valve can be a bi-leaflet or a tri-leaflet valve. The bi-leafletvalve includes a frame, a tissue cover, a deformable hinge, and meansfor detachably connecting the valve to the valve cage stent. The framehas two substantially semicircular, expandable, and compressible parts,and the tissue cover is configured to cover the two parts of the framewith the straight sides of the two parts in spaced-apart relation. Thetissue cover has a central aperture and the two parts of the frame haverespective slots. The deformable hinge has oppositely extending armsextending through the slots and a stem received through the aperture.The superior rim of the valve cage stent has a valve mount affixedthereto for receiving a mating part on the hinge, thereby defining theattachment means.

The tri-leaflet valve includes a frame, a tissue cover, and means fordetachably connecting the valve to the valve cage stent. The frame iscylindrical and has three commissural posts mounted thereon. The tissuecover has three cusps fitted and sewn to the valve frame, thecommissural posts being sized to maintain the commissural height of thecusps. The valve cage stent has three commissural pins extending fromthe superior rim thereof, and the commissural posts of the frame arecannulated to receive the commissural pins of the valve cage stent,thereby defining the attachment means.

Other objects, features and advantages of the present invention will beapparent to those skilled in the art upon a reading of thisspecification including the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is better understood by reading the following DetailedDescription of the Preferred Embodiments with reference to theaccompanying drawing figures, in which like reference numerals refer tolike elements throughout, and in which:

FIG. 1 is a diagram of a valve prosthesis in accordance with the presentinvention.

FIG. 2A is a diagrammatic plan view of a frame for a bi-leafletpercutaneous heart valve in accordance with the present invention.

FIG. 2B is a diagrammatic plan view of a tissue cover for the frame ofFIG. 2A.

FIG. 2C is a diagrammatic plan view of an assembled bi-leafletpercutaneous heart valve in accordance with the present invention,incorporating the frame of FIG. 2A and the tissue cover of FIG. 2B.

FIG. 2D is a diagrammatic side elevational view of the bi-leafletpercutaneous heart valve of FIG. 2C in the open position.

FIG. 2E is a diagrammatic side elevational view of the bi-leafletpercutaneous heart valve of FIG. 2C in the closed position.

FIG. 2F is a top perspective view of an assembled bi-leafletpercutaneous heart valve in accordance with the present invention, inthe closed position.

FIGS. 2G and 2H are top and side perspective views of the bi-leafletpercutaneous heart valve of FIG. 2F in the open position.

FIGS. 2I and 2J are side perspective views of the valve cage stent foruse with the bi-leaflet percutaneous heart valve of FIG. 2F.

FIG. 2K is a partial perspective view of the bi-leaflet percutaneousheart valve of FIG. 2F mounted on the valve cage stent of FIG. 2I, withthe valve in the closed position.

FIG. 2L is a partial perspective view of the bi-leaflet percutaneousheart valve of FIG. 2F mounted on the valve cage stent of FIG. 2I, withthe valve in the open position.

FIG. 3A is a diagrammatic perspective view of a frame for a tri-leafletpercutaneous heart valve in accordance with the present invention.

FIG. 3B is a perspective view of a tissue cover for the frame of FIG.3A.

FIG. 3C is a perspective view of an assembled tri-leaflet percutaneousheart valve in accordance with the present invention, incorporating theframe of FIG. 3A and the tissue cover of FIG. 3B

FIG. 3D is a side perspective view of the valve cage stent for use withthe tri-leaflet percutaneous heart valve of FIG. 3C.

FIGS. 3E and 3F are top perspective views of the valve cage stent foruse with the tri-leaflet percutaneous heart valve of FIG. 3C.

FIG. 3G is a diagrammatic view of a portion the valve cage stent for usewith the tri-leaflet percutaneous heart valve of FIG. 3C, which as beenopened up and flattened for purposes of illustration.

FIG. 3H is a partially cut-away perspective view of the tri-leafletpercutaneous heart valve of FIG. 3C mounted on the valve cage stent ofFIG. 3D, in the undeployed condition.

FIG. 3I is a partially cut-away perspective view of the tri-leafletpercutaneous heart valve of FIG. 3C mounted on the valve cage stent ofFIG. 3D, in the deployed condition.

FIGS. 4A-4G show the sequence of steps in implantation of the bi-leafletpercutaneous heart valve prosthesis of FIG. 2C in an aorta, in which thevalve is attached to the valve cage stent outside the delivery catheter.

FIGS. 5A-5I are diagrammatic representations of the sequence of steps inimplantation of the bi-leaflet percutaneous heart valve of FIG. 2C, theaorta being omitted from all of FIGS. 5A-5I and the valve cage beingomitted from FIGS. 5A-5F for clarity.

FIGS. 6A-6J show the sequence of steps in implantation of thetri-leaflet percutaneous heart valve of FIG. 3C in an aorta, in whichthe valve is attached to the valve cage stent outside the deliverycatheter.

FIGS. 7A and 7B are exploded and assembled views, respectively, of thedelivery system apparatus used in implantation of the bi-leaflet andtri-leaflet valves in accordance with the present invention.

FIG. 7C is an end view of the flexible sheath of the delivery systemapparatus of FIGS. 7A and 7B.

FIG. 8 is a side view of a valve cage stent mounted on a ballooncatheter.

FIGS. 9A-9T show the sequence of steps in implantation of thetri-leaflet percutaneous heart valve of FIG. 3C in an aorta, in whichthe valve is attached to the valve cage stent within the deliverycatheter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In describing preferred embodiments of the present invention illustratedin the drawings, specific terminology is employed for the sake ofclarity. However, the invention is not intended to be limited to thespecific terminology so selected, and it is to be understood that eachspecific element includes all technical equivalents that operate in asimilar manner to accomplish a similar purpose.

The present invention relates to heart valve prostheses that can beimplanted percutaneously by means of a catheter from a remote locationwithout opening the chest cavity. As shown in FIG. 1, the valveprosthesis 10 comprises two parts, (1) a valve cage stent 20 constructedto be implanted in the planar axis of the native valve annulus, (2) anelastic and compressible valve 30, and (3) an attachment mechanism forattaching the valve 30 to the superior rim of the above mentioned valvecage stent 20. In accordance with the present invention, two types 110and 210 of heart valve prosthesis 10 are contemplated, one type 110incorporating an elastic and compressible bi-leaflet hinged valve 130(shown in FIGS. 2A-2E) and the other type 210 incorporating an elasticand compressible tri-leaflet biologic valve 230 (shown in FIGS. 3A-3C).A system and method for implanting the valves (shown in FIGS. 4A-4G,5A-5I, and 6A-6J) is also encompassed by the invention.

Referring now to FIGS. 2A-2H, the bi-leaflet tissue valve 130 comprisesa two-part (that is, a two-leaflet) frame 132 made from a memory metalwire or strip and a tissue cover 133. As best shown in FIG. 2A, eachpart 132 a and 132 b of the frame 132 is substantially semicircular.Portions of each part 132 a and 132 b of the frame 132 (for example, thestraight side and the center portion of the curved side) are configured(for example, by having a sinusoidal configuration, shown by brokenlines in FIGS. 2A and 2C) so that each part 132 a and 132 b of the frame132, as well as the frame 132 as a whole, is expandable andcompressible, while the remaining portions of the frame 132 are notexpandable and compressible.

Each part 132 a and 132 b of the frame 132 includes a slot 134 forreceiving a hinge 135 having a shape when deployed that is similar to alower-case “t”, as shown in FIGS. 2D and 2E, having two aims 135 a and135 b and a stem 135 c. The slot 134 is formed unitarily with the frame132. The “t”-shaped hinge 135 is stamped out of memory metal (forexample, nitinol) sheeting so that it is deformable. The arms 135 and135 b of the hinge 135 have projections 135 d at their ends, whichfunction as stops for the leaflets. The stem 135 c of the hinge 135 hasa snap-on or screw-in mechanism 141 for attachment to a valve mount 142(shown in FIGS. 2I-2L), as described below.

The tissue cover 133 (shown in FIG. 2B) is made, for example, of equineor bovine pericardium, or various synthetic materials, for example, ormedical grade silicone, fabric, or other compressible, materials, and isconfigured to cover the two parts 132 a and 132 b of the frame 132 withtheir straight sides in spaced apart relation, with a central aperture133 a in the center for receiving the stem of the “t”-shaped hinge 135and two side apertures 133 b in alignment with the slots 134 forreceiving the arms 135 a and 135 b of the hinge 135. The tissue cover133 is sewn to each part 132 a and 132 b of the frame 132, as shown inFIGS. 2C and 2F-2H, and thus connects the two parts 132 a and 132 b ofthe frame 132 in spaced-apart relation.

As discussed in greater detail below, in use, the bi-leaflet valve 130is detachably connected to a valve mount 142 (shown in FIGS. 2I and 2I)via the “t”-shaped hinge 135, as shown in FIGS. 2K-2N, 4D-4G, and 5G-5I.The valve mount 142 is also made from a memory metal so that it iscollapsible. More specifically, the valve mount 142 has arms 142 a and142 b on either side of a receptacle 142 c, which are folded upvertically when the valve cage stent 120 is in its compressed(undeployed) condition, the ends of the arms 142 a and 142 b beingaffixed to the valve cage stent 120.

The detachable and collapsible bi-leaflet construction of the valve 130enables the valve 130 in conjunction with its entire delivery system tobe sized down so that it can be inserted percutaneously using acatheter, as described below.

Referring now to FIGS. 3A-3C, the tri-leaflet tissue valve 230 comprisesan expandable and compressible valve frame 232 (shown in FIG. 3A) madefrom a memory metal wire or strip and a tissue cover 233 (shown in FIGS.3B and 3C). The tissue cover 233 is made from the individual cusps of aporcine aortic valve sewn to appropriate fabric. Three identical cuspsare selected. Two or more pigs are used to get ideal sized aortic cusps.The muscle bar cusp is preferably not used; and all of the sinus andsurrounding tissue is S discarded. The commissural height is maintainedat all cost. The tissue cover 233 (that is, the cusps sewn to thefabric) is fitted and sewn to the valve frame 232. The valve frame 232has three cannulated commissural posts 240 a, 240 b, and 240 c mountedthereon, and the tissue cover 233 is sewn to the commissural posts 240a, 240 b, and 240 c to complete the tri-leaflet valve 230 (FIG. 3C).

As shown in FIGS. 3A-3C, the tri-leaflet valve 230 is mounted oncommissural pins 240 aa, 240 bb, and 240 cc provided on a valve cagestent 220 of the type disclosed in provisional application No.60/735,221, which is incorporated herein by reference in its entirety.More specifically, the commissural posts 240 a, 240 b, and 240 c of thevalve frame 232 are cannulated to receive the commissural pins 240 aa,240 bb, and 240 cc, respectively, of the valve cage stent 220, therebyconnecting the valve frame 232 (and thus the valve 230) to the valvecage stent 220. As described below, the heart valve prosthesis 210incorporating the tri-leaflet valve 230 is delivered using a catheter.

As shown in FIG. 3G, the valve cage stent 220 for use with thetri-leaflet valve 230 has three different zones 221, 222, and 223 alongits longitudinal axis, the different zones having different geometricconfigurations so as to perform different functions. The first, orcenter, zone 221 functions as the stent connector, which is identical tothe stent disclosed in Int'al Patent Application No. PCT/US2006/043526,filed Nov. 9, 2006 (which is based on U.S. Provisional Application No.60/735,221), and which connects to the native valve annulus. The secondand third zones 222 and 223, at either end of the center zone 221,function respectively as the superior valve rim carrying the commissuralpins in the tri-leaflet valve prosthesis 210 or the valve mount in thebi-leaflet valve prosthesis 110, and the inferior valve skirt. The valveskirt 223 provides additional support, as well as a fabric/tissueattachment area to minimize leaking.

The present invention also encompasses a system and method forimplanting the above-described percutaneous valve prostheses 10 in thebody. In a first embodiment, the system comprises a valve cage stent 20for implantation in the body by the use of a first catheter of adelivery system 500 (shown in FIGS. 8A and 8B, and as described ingreater detail hereinafter) to provide a stable, fixed, and sturdy framewithin which an elastic, compressible valve 30 can be inserted andsecured by a second catheter (not shown), and the valve 30 is attachedto the valve cage stent 20 after they are discharged from theirrespective catheters. Performing the procedure in two parts at the samesession downsizes the devices considerably, so that the procedure can beperformed percutaneously. In a second embodiment, the system comprises avalve cage stent 20 and an elastic, compressible valve 30 which areinserted using the same catheter, and the valve 30 is attached to thevalve cage stent 20 within the catheter, as shown in FIGS. 9A-9T.

The valve cage stent 20 is a self-expanding or balloon expandablecylindrical valve cage stent 20, made from memory metal, or stainlesssteel respectively. The self-expanding valve cage stent and the balloonexpandable valve cage stent are structurally the same (that is, theydiffer only in the material from which they are made). The valve cagestent 20 is fabricated from metal tubing (memory metal or stainlesssteel), so that it is cylindrical in shape, with the stent pattern beingcut into the tubing by laser.

The expansion of the valve cage stent 20 produces maximal foreshorteningof the ovals in the mid portion of the stent and thus provides activefixation of the stent to the annulus of the valve being replaced. Thevalve cage stent 20 has a fabric covering on its interior and parts ofits exterior surfaces so in its expanded state it forms a complete sealand does not allow any leakage of blood.

For delivery, the valve cage stent 20 is mounted on a balloon 600 (FIG.8), or in a restraining sheath if self-expandable. The delivery systemapparatus 500 is shown in FIGS. 7A-7C. The delivery system apparatus 500comprises a flexible outer sheath 510, in which the valve cage stent 20is inserted with a first set of guide wires 520 attached thereto,followed by a slotted nosecone 530 having another set of guide wires 540attached thereto.

The valve cage stent 20 has provisions for the attachment of theprosthetic valve, depending on the type of prosthetic valve contemplatedto be used. For example, in the case of a bi-leaflet valve, the valve isattached to the valve cage stent 120 via a valve mount affixed to thevalve cage stent 120, as shown in FIGS. 4D-4G and 5G-5I. In the case ofa tri-leaflet valve, the valve is attached to the valve cage stent 220via engagement of the valve commissural posts 240 a, 240 b, and 240 cwith the commissural pins 240 aa, 240 bb, and 240 cc of the valve cagestent 220, as shown in FIGS. 6H-6J.

The delivery system employs a two stage procedure, both stages of whichcan be performed at the same session, only minutes apart. The firststage is insertion of the valve cage stent 20. In the case of abi-leaflet valve, as shown in FIG. 4A, the valve cage stent 120 has avalve mount connected thereto and a guide wire connected to the valvemount. In the case of a tri-leaflet valve, as shown in FIGS. 6A-6G andas described above, the valve cage stent 220 has three commissural pins240 aa, 240 bb, and 240 cc provided thereon and guide wires connectedthereto.

The second stage is insertion of the elastic and compressible valve,which is restrained in another catheter (not shown) for delivery intothe valve cage stent 20. As shown in FIGS. 4A-4D, 5A-5F, and 6A-6H, inthe second stage, the valve is placed over the guide wire (in the caseof a bi-leaflet valve) or guide wires (in the case of the tri-leafletvalve) connected to the valve cage stent 20 in order to ensure properpositioning of the valve relative to the stent. Once the valve isseated, the guide wire or wires are withdrawn (FIGS. 4D-4G, 5G-5I, and6I-6J).

Because the bi-leaflet valve is detachable from the valve mount, it canbe replaced when necessary. The valve mount has a snap-on or screw-inmechanism for attachment of the “t”-shaped hinge 135 thereto, as well asthe above-described guide wire attached to it for placement of thevalve. The use of a valve cage 20 allows for fabrication of atri-leaflet tissue valve.

In addition, the connection of valve 30 to the valve cage stent 20provides the best effective flow dynamics, the flexibility of the wholesystem 500 is greatly increased, and the profile of the whole system 500is reduced so that it can be inserted through a small opening in theaccess vessel.

Modifications and variations of the above-described embodiments of thepresent invention are possible, as appreciated by those skilled in theart in light of the above teachings. It is therefore to be understoodthat, within the scope of the appended claims and their equivalents, theinvention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A method for delivering a heart valve prosthesisto a native valve annulus, the method comprising: delivering a firstexpandable frame mounted on or within a delivery device to the nativevalve annulus, the first expandable frame comprising a first anchoringportion and a second anchoring portion; expanding the first expandableframe at the native valve annulus, wherein when the first expandableframe is in an expanded configuration: the first anchoring portionextends radially outwardly of a longitudinal axis of the firstexpandable frame and is positioned on a first side of the native valveannulus; the second anchoring portion extends radially outwardly of alongitudinal axis of the first expandable frame and is positioned on asecond side of the native valve annulus; the first anchoring portionengages tissue on the first side of the native valve annulus and thesecond anchoring portion engages tissue on the second side of the nativevalve annulus to secure the first expandable frame to the native valveannulus; and positioning at least a portion of a replacement heart valvewithin the first expandable frame, the replacement heart valvecomprising a second expandable frame and a valve body comprising aplurality of leaflets.
 2. The method of claim 1, wherein at least aportion of the replacement heart valve is positioned within the firstexpandable frame after expanding the first expandable frame at thenative valve annulus.
 3. The method of claim 1, wherein at least aportion of the replacement heart valve is positioned within the firstexpandable frame before expanding the first expandable frame at thenative valve annulus.
 4. The method of claim 1, wherein positioning atleast a portion of the replacement heart valve within the firstexpandable frame comprises attaching the replacement heart valve to thefirst expandable frame.
 5. The method of claim 4, wherein thereplacement heart valve comprises at least one commissural post and thefirst expandable frame comprises at least one commissural pin, whereinattaching the replacement heart valve to the first expandable framecomprises attaching the at least one commissural pin with the at leastone commissural post.
 6. The method of claim 5, wherein the at least onecommissural post is cannulated and wherein attaching the at least onecommissural pin with the at least one commissural post comprisesreceiving the at least one commissural pin within the at least onecommissural post.
 7. The method of claim 1, wherein positioning at leasta portion of the replacement heart valve within the first expandableframe comprises expanding the replacement heart valve.
 8. The method ofclaim 1, wherein the first expandable frame comprises a superior end andan inferior end, wherein after positioning at least a portion of thereplacement heart valve within the first expandable frame, at least aportion of the replacement heart valve is positioned past the superiorend of the first expandable frame in a superior direction.
 9. The methodof claim 1, wherein when the first expandable frame is in an expandedconfiguration, the first anchoring portion extends at least partiallytowards the first side of the native valve annulus.
 10. The method ofclaim 1, wherein the second anchoring portion comprises a plurality ofanchors and wherein at least a portion of at least one of the pluralityof anchors extends towards the first anchoring portion.
 11. The methodof claim 1, wherein the first expandable frame comprises a skirt at aninflow end of the first expandable frame.
 12. The method of claim 11,wherein the first expandable frame further comprises a fabric attachedto the skirt configured to reduce leakage.
 13. The method of claim 1,wherein the first expandable frame self-expands into the expandedconfiguration at the native valve annulus.
 14. The method of claim 1,wherein the second expandable frame of the replacement heart valveself-expands.
 15. The method of claim 1, wherein the native valveannulus is a native aortic valve annulus.
 16. The method of claim 1,wherein the valve body comprises a tri-leaflet valve.
 17. A method fordelivering a heart valve prosthesis to a native valve annulus, themethod comprising: delivering a first expandable frame mounted on orwithin a delivery device to the native valve annulus, the firstexpandable frame comprising superior and inferior ends, a firstanchoring portion and a non-foreshortening portion; expanding the firstexpandable frame at the native valve annulus, wherein when the firstexpandable frame is in an expanded configuration: the first anchoringportion extends radially outwardly of a longitudinal axis of the firstexpandable frame and is positioned on a superior side of the nativevalve annulus, the first anchoring portion engaging tissue on thesuperior side of the native valve; and the inferior end is positioned onan inferior side of the native valve annulus; and positioning at least aportion of a replacement heart valve within the first expandable framein the non-foreshortening portion, the replacement heart valvecomprising a second expandable frame and a valve body.
 18. The method ofclaim 17, wherein at least a portion of the replacement heart valve ispositioned within the first expandable frame after expanding the firstexpandable frame at the native valve annulus.
 19. The method of claim17, wherein the non-foreshortening portion comprises a plurality ofstruts.
 20. The method of claim 17, wherein positioning at least aportion of the replacement heart valve within the first expandable framecomprises attaching the replacement heart valve to the first expandableframe.
 21. The method of claim 20, wherein the replacement heart valvecomprises at least one commissural post and the first expandable framecomprises at least one commissural pin, wherein attaching thereplacement heart valve to the first expandable frame comprisesattaching the at least one commissural pin with the at least onecommissural post.
 22. The method of claim 21, wherein the at least onecommissural post is cannulated and wherein attaching the at least onecommissural pin with the at least one commissural post comprisesreceiving the at least one commissural pin within the at least onecommissural post.
 23. The method of claim 17, wherein after positioningat least a portion of the replacement heart valve within the firstexpandable frame in the non-foreshortening section, at least a portionof the replacement heart valve is positioned past the superior end ofthe first expandable frame in a superior direction.
 24. The method ofclaim 17, wherein the first expandable frame self-expands into theexpanded configuration.
 25. The method of claim 17, wherein the firstexpandable frame further comprises a second anchoring portion, andwherein when the first expandable frame is in an expanded configuration,the second anchoring portion extends radially outwardly of thelongitudinal axis of the first expandable frame.
 26. The method of claim17, wherein the valve body comprises a tri-leaflet valve.